Usually the airline would rebook you automatically. They will refer you to the travel agent if you wish to initiate a change, but if it is their issue I have never not had them handle it themselves. It is your responsibility to check the flight status periodically and also a VERY good idea to make sure your trip and phone/e-mail are known to the airline so they can notify you.

Check the terms and conditions of your ticket along with the contract of carriage for the airline. Those will spell out all of the rules.

"The also refused to help as, in their view, 'the airline had chosen to cancel the flight' so Expedia were exonerated of any further commitment. "

Bollocks, Expedia should have rebooked you. They even say on their website to call them for assistance if your flight is affected by the strike.

>>>Does anyone know who is responsible for rebooking flights in the event of a cancellation when the initial booking is made through an online agent?<<<

Since Regulation 261/2004 which covers what happens in the event of a cancellation makes no mention of an 'agent' whether online or not, I would tend to lean towards what the Regulation states as this is the legal framework under which a passenger would seek to continue their onward journey.

The Regulation states that it is the operating airline's responsibility to offer the passenger a choice between either a re-route or a full refund.

The answer to the OP's question is therefore the airline.

Vueling 2 Expedia 2

I'm confused.

Vueling are legally obliged to rebook you as Travelomancity says but since you booked through Expedia you will normally be expected to sort it out through them (I've got no idea about the legality of the airline insisting on that but it's just how it is when you book through a 3rd party, they will always refer you book to the booking agent if you want to make changes. A refund would go through Expedia as well). It's usually not an issue and I suspect the CSR you talked to at Expedia simply gave you wrong information. As I said, Expedia even has info on their website for passengers affected by the strike and I have had them sort out rebooking in the past myself.

The airline is responsible IMV. …europa.eu/transport/…03-air.html for the details.

Thank you to those who responded. I wanted to let you know that after some communication with Expedia they have agreed to refund the cost of the new flights we were forced to book. Although not said in as many words they more or less admitted that they should have rebooked the flights for us.

I am grateful to Expedia but you live and learn. In the future I'll book direct with the airline even though it may cost a bit more.

Thanks for coming back and letting us know the outcome.

In the meantime you are entitled to €250 each under EU261 if the airline cancelled the flight without a valid extraordinary circumstance.